Stewart j



Patented Sept. 4, 1923.

UNITED STATES PATENT OFFICE.

STEWART J. CARROLL, OF ROCHE TER. NEVI YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION 03? NEW YORK.

CELLULOSE-E'IHER SOLVENT AND COMPOSITION.

No Drawing.

To Q17] whom it may concern:

Be it known that I, STEWART J. CAnRoLL, a. citizen of the United States of America, residing! at Rochester, in the county of Monroe and State of New York, have invented. certain new and useful Improvements in Cellulose-Ether Solvents and Compositions, ot which the following is a full, clear, and exact specification.

This invention relates to solvents for male inc; strong solutions of cellulose ether and also relates to the cellulose ether compositions produced by the aid of such solvents. (lne object of my invention is to provide a solvent which will dissolve such large proportions of cellulose ethers that thick or viscous flowable solutions may be obtained for use in plastic and film making arts. Another obj ect of my invention is to provide a cellulose ether solution which may be manutactured into strong, flexible, transparent film on the machines and by the methods now in use.

In U. S. Patent No. 1,188,376, Lilienfeld, June 20, 1916, there are disclosed a series of alltyl ethers of cellulose. Certain of these are practically insoluble in water, and my in ention relates but is not limited to the others having that property. While the others form thin solutions in methyl acetate or inonochlornaphthalene, it has been found that such single solvents by then'isclves will not dissolve a su'flicient proportion of the ethers to make a desirably thick floWabl-e composition or dope, such, asmay be used in the manufacture of photographic film base by the customary methods, and in the other plastic arts.

I have discovered that an adequately strong and useful solvent may be prepared by mixing methyl acetate with a co-operat ing' solvent, like monochlornaphthalene. The proportions of the mixture may vary widely, but I find that useful solvents may be prepared for instance, by mixing from 50 to 60 parts by weight of methyl acetate with 50 to 40 parts of monochlornaphthalene. While the amount of cellulose ether which may be dissolved in my compound Application filed April 5, 1921. Serial No. 458,742.

solvents can be altered considerably, ll find the following illustrative proportions to be useful. 1 part of water-insoluble cellulose is dissolved in 5 parts of my compound solvent, giving a thick viscous flowable solution. (Ether substances which impart additional suppleness, or incon'iluistibility, or other qualities, to the film may be added to the dope, such, for example, triphenyl. phosphate, tricresyl phosphate, camphor. etc.

The ingredients are oi the ordinary commercial type and su'ficiently purified tor the process of film manufacture, so as to give a dope yielding lilnis having the proper relative freedom from color. The Viscous tlowable dope above described can be used in connection with the usual film-torminn apparatus without the necessity of expensive alterations in the latter.

.l-laving thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A compound solvent for alkyl others of cellulose, comprising methyl acetate and monochlornaphthalene.

2. A compound solvent for alkyl ethers of cellulose, comprising 50 to parts by weight oi methyl acetate and 50 to parts by weight of monochlornaphthalene.

3. A viscous fiowable film-forming composition. comprising an alkyd ether of cellulose dissolved in a. mixture of methyl acetate and monochlornaphthalene.

A. viscous tlowahle film-forming composition. comprising an alkyl ether of cellulose dissolved in a compound solvent contaming from to parts by weight of methyl acetate and from 50 to 0 parts of monochlornaphthalene.

A. composition of matter coimirising 1 part of water-insoluble ethyl cellulose dissolved in approximately 5 parts by weight of a. compound solvent containing methyl acetate and monochlornaphthalene.

t ned at Rochester, New York, this 30th day of March, 1921.

STEl/VART J. CARROLL. 

